The temperature is getting higher, these things need to pay attention to the printing shop
Time:2023-07-10
Views:1675
Concern 1: Temperature and humidity will affect the performance of paper and ink
Paper is composed of plant fibers, which are porous and hydrophilic, and are very sensitive to water. If the ambient temperature and humidity change slightly, the water content of paper will change. The effect of the relative humidity of air on the water content of paper is generally that the relative humidity increases, the water content of paper increases, and conversely, the relative humidity decreases, and the water content of paper decreases.
The influence of temperature change on the water content of paper is different. Generally, the temperature increases and the water content of the paper decreases. The water content of the paper is directly related to the printing performance. For example, changes in the water content of the paper will cause the paper to expand (including local deformation). The dimensional stability of paper has a great relationship with the operational suitability and registration suitability of printing. In particular, multi-color overprinting products, paper size changes, will cause the product overprinting is not allowed, become defective, waste. Therefore, the size change of paper affected by temperature and humidity is one of the most important problems in the printing shop.
Due to the change in the water content of the paper, it will also cause changes in other properties of the paper. If the water content increases, the tensile strength and surface strength of the paper decrease; The water content is too low, the paper becomes brittle and hard, and the phenomenon of electrostatic charge is easy to produce when printing.
Various printing inks are affected by temperature and humidity to varying degrees. In general, the higher the temperature, the faster the drying; The lower the temperature, the slower the drying. In particular, the ink of the lithographic printing process, in the printing process, due to the presence of the plate liquid, will cause emulsification, so the relative humidity affects the evaporation of water in the ink. Therefore, temperature and humidity have a direct impact on the drying speed of the ink, if the temperature is too low, the relative humidity is too large, will reduce the drying speed of the ink, extend the printing cycle.
The ambient temperature and humidity will also affect the viscosity of the ink. The viscosity of ink decreases with the increase of ambient temperature. The ambient temperature decreases and the ink viscosity increases. If the temperature is too low and the ink viscosity is too large, there will be printing failures, such as local peeling of the paper surface and sticking to the rubber sheet or plate. Therefore, controlling the temperature and relative humidity of the printing shop can control the drying speed of the ink and printing faults.
Concern 2: The workshop temperature is too high to affect the normal work of printing equipment
1) The wear of the mechanical part will be intensified;
2) The impact on the electrical part is greater, the control of the motor, air pump, oil pump, etc. on the offset press is protected by the thermal appliance, the temperature is too high, there will be overload protection action, affecting the normal work, especially the inverter of the main motor should refuse high temperature, and high temperature will also cause a fire.
Temperature and humidity changes have a great impact on the normal production of the printing shop.
Practice has proved that the best working environment temperature of the printing workshop is 18 ° C ~23 ° C, and the relative humidity is 55%~65%. Printing enterprises can use the dehumidification and humidification machine to create a relatively stable production environment for the workshop.
Enterprises should promptly respond to the "high" temperature, for the hot production workshop must do a good job of cooling, ventilation measures, not only the guarantee of printing supplies storage quality, but also the guarantee of the physical safety of front-line employees in printing production.